Quantitative evaluation of interdiffusion in Fe2Al5 during reactive diffusion in the binary Fe-Al system
Quantitative evaluation of interdiffusion in Fe2Al5 during reactive diffusion in the binary Fe-Al system
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DOI：
10.2320/matertrans.47.1480
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发表时间：
2006-06-01
影响因子：
1.2
通讯作者：
Kajihara, Masanori
中科院分区：
文献类型：
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作者：
Kajihara, Masanori
采用扩散连接技术制备Al/Fe/Al扩散偶，对Fe-Al二元系中的反应扩散进行了实验研究。在T = 823-913 K的温度下对扩散偶进行等温退火，然后观察到在界面处形成Fe 2Al 5化合物层。结果表明，Fe_2Al_5层的平均厚度与退火时间之间存在抛物线关系。抛物线关系意味着Fe 2Al 5层的生长受体积扩散控制。采用体积扩散控制的反应扩散数学模型对Fe 2Al 5层的生长速率进行了数值分析。通过分析，计算出Fe_2Al_5在T = 823、873和913 K时的互扩散系数D分别为5.93 × 10 ~（-16）、1.18 × 10 ~（-14）和2.92 × 10 ~（-14）m ~（2）/s。将D的温度依赖性表示为D D-0 exp（-Q/RT），通过最小二乘法得到D-0 = 2.34 x 10（2）m（2）/s和Q = 276 kJ/mol。
Using Al/Fe/Al diffusion couples prepared by a diffusion bonding technique, the reactive diffusion in the binary Fe-Al system was experimentally examined in a previous study. The diffusion couple was isothermally annealed at temperatures of T = 823-913 K, and then a compound layer of Fe2Al5 was observed to form at the interface. The observation indicates that there exists the parabolic relationship between the mean thickness of the Fe2Al5 layer and the annealing time. The parabolic relationship means that the growth of the Fe2Al5 layer is controlled by volume diffusion. A mathematical model for the reactive diffusion controlled by volume diffusion was used in order to analyze numerically the growth rate of the Fe2Al5 layer. Through the analysis, the interdiffusion coefficient D of Fe2Al5 was evaluated to be 5.93 x 10(-16), 1.18 x 10(-14) and 2.92 x 10(-14) m(2)/s at T = 823, 873 and 913 K, respectively. Expressing the temperature dependence of D as D D-0 exp(-Q/RT), values of D-0 = 2.34 x 10(2) m(2)/s and Q = 276 kJ/mol were obtained by the least-squares method.